Challenging the Realms of Sanity
by Gasterade
Summary: Gaster has been planning the second installation of his project for a while now. It's not going to be exactly what you'd expect. Can you handle the Donkey-Kong-Country-style roller coaster of emotion?
1. Chapter 1

The lab was quiet. Dr. Gaster stood alone at the table at the far end of the white room, slightly hunched over. He held something in his hands - in the holiest of hands - trembling the slightest in anticipation. "Sans," he said.

A moment passed. There was no answer.

"Sssssssssss-" Gaster began to turn, his eye sockets and mouth widening, "-SSSSSSSSAAAAAAAAANNNNNNNSSSSSSSS," he shrieked, pupils dilating to star-bright silver dollars, his overexuberance manifesting itself in physical ways as it so often did.

There was a series of rapid thumps followed by the sight of Sans the skeleton crashing into the bottom of the stairwell on the opposite end of the room, clutching his chest tightly in one hand and supporting himself with the other. He was wearing a lab coat identcal to Gaster's, albeit far shorter, and a set of goggles which had cracked in the impact between his skull and the vestibule.

"Jesus Christ, what is it," Sans gasped, still trying to catch his breath. His pseudo-lungs heaved and a cold sweat had already begun to break out on his brow. What was it this time.

Gaster had already swooped over, gently and towering, his body inclined over Sans with an almost parental sternness. Almost, but there was the everpresent tinge of mania the doctor's son had come to expect; Sans kept his protective barrier of hesitation up strong as his father proffered a strange contraption before his eyes, with an almost loving caress. It was a strangely colorful, elongated...and-

"Is that a gun?" The shorter skeleton asked with a creeping degree of incredulity.

"Take it, son," insisted Gaster, grasping the younger skeleton's hand in his own and forcing the object gently into his grip. "Take this."

"What...what do you want me to do with it? What does it do?" Sans asked almost fearfully, turning the obviously-gun-like invention over in an analytical fashion. Its frame looked somehow...skeletal, like most of Dr. Gaster's inventions. It looked mildly scuffed, like it had been used before.

Gaster suddenly put both hands on Sans's shoulders, tender yet firm. He stared him dead in the eye, the single crack running along his temple all too visible in the incandescent light swinging gently above them. "Son," he said seriously. "Do you trust me?"

Sans's expressed turned hesitantly earnest, despite the permanently affixed grin which would ceaselessly assist to define him as a person. "Of course," he said. " 'course I trust you, G...but-"

"Then there is no time!" Gaster blurted, positioning the gun in San's hands so that it was at arm's length and aiming directly for Gaster's head. "You must do it now. Pull the trigger, son!"

"What!?"

"THERE IS NO TIME!" shrieked Gaster. "DO IT NOW! HURRY! HURRY, MY SON!"

In the chaos, Sans managed to fumble, through his own reciprocal screaming, and press the trigger which caused a brilliant white beam of light to deploy itself directly at Gaster's head. The scientist was blasted backward about seven meters and hit the table at the opposite wall with a crack, collapsing backward over it and lying motionless.

"Oh God, oh God, oh God," Sans muttered, casting aside the now-useless goggles that had been obscuring his vision. He scrambled over to where the doctor lay, body strewn across the pristine white surface of the table, and gingerly touched Gaster's slightly smoking labcoat. "G?" Sans's voice was shaky. "G, are you...are you-"

"Brilliant work, son!" Exclaimed the scientist in both English and Wing Dings, such was his excitement; his eyes shot open wide and a great smile split his skeletal face, the smile which he reserved for only the most greatest revelation in his accomplishments. The cracking of this particular smile, Sans had come to know very well, was analogous to popping the cork off a bottle of champagne. "What is going on?" Sans asked, his voice now steadied and his shoulders relaxing the slightest bit as he searched Gaster's face. He peered down at the thing still clasped in his own skeletal hands, which, despite realistically expectable consequences, had broken out in a cold sweat. The device slipped fractionally in his slick grip and he attempted to readjust his hold on it, but Gaster smacked it out of his hand. "No need for that anymore!" He proclaimed through his wide smile. "We may cast it aside for now. Our work is done!"

Sans raised a cautious brow. "Our...work?"

"Indeed." Gasted swiveled upright into a sitting position, brushing himself off in a professional manner.

"Oh, God," Sans suddenly said, noticing for the first time that something orange was leaking down the doctor's face. "Are you...bleeding? Is that blood?"

"Hmm?" Gaster withdrew a handkerchief from his pocket and dabbed at his eye, and only smiled wider when it came away a brilliant orange. A trickle of deep orange remained on the scientist's once-good remaining eye which, Sans now also realized, had a fresh crack to match the other, this time running down to his upper lip. If he had lips. "No, no," Gaster chuckled gently. "This is only magical residue, the last of this particular essence from my soul's spectrum. That essence extractor really did the job!" He turned slowly up from the handkerchief to face Sans then, an almost somber expression on his face as he asked, "Orange you glad?"

Emotions, so many conflicting emotions, churned within the solid confines of Sans's skull. Still, he chortled heartily. Sans wasn't even sure where in his soul the laughter came from this time, but he didn't really care; his mentor was safe. He helped Gaster up from where he sat on the lab table and grasped the doctor firmly by the hands (he couldn't reach his shoulders); this was important. "Gaster?" he asked. "What essence did we just extract from you?" He cast a fleeting glance over at the gun-like object now lying several feet away fro them on the floor. Now that he could spare a moment to give it thought, he realized the design was bizarrely reminiscent of a combination between a glock and a bubble wand.

Before answering Sans's question, Gaster stepped over to retrieve the essence extractor, only mildly staggering from the aftereffects of having presumably removed a significant portion of his soul. He brought it up gingerly, almost lovingly to his excited face, which wasn't plastered with as wide a smile as before. It was his serious face. "I have a surprise for you, Sans."

Sans's brow creased only slightly.

"You've always seemed so lonely, my son," Gaster continued, as he unloaded a capsule from the device. It glowed a brilliant red-orange. he took it between two of his long, skeletal fingers and examined it contemplatively. "It took me a long time to realize that there may be some needs in a young monster's life that science and labwork simply can't fulfill." He turned then to gaze at Sans, an unfathomable expression on his gasterly face. "Then, of course, I came to my senses because science is literally the answer to everything, so I'm making you a brother!"

Sans remained silent for a long time as he watched Gaster's expectant face eventually turn, undaunted, to the strange tank beside the desk in the corner of the room and gently place the capsule, now glowing brilliantly vermillion, into the vat of clear liquid with a pair of spaghetti tongs. he then began stirring it gently with the tongs, humming to himself slightly. Finally, after a few minutes, but what seemed to Sans like years, Gaster beckoned him over and said in an excited yet hushed voice, "Come, look at him grow!"

Sans shuffled over in his lab slippers, the initial shock of the last four minutes being swifly replaced by a growing curiosity. Despite himself, he was a scientist just like Gaster, and the very real intellectual need to observe the potentially terrifying repercussions of Gaster's 'surprise' overrode any apprehensive dread. Still, he forced himself to again ask, "Gast, what essence did we just extract from you? What is growing in that aquarium? This...seems...pretty fishy if you ask me," he heard himself add compulsively.

Gaster whirled around with the familiar grin on his face, though the lights of his pupils had since gone out. "It is an incubation tank, Sans," he responded gleefully. "The same one you were created in."

There was a long moment in which Sans resigned himself to something.

"I didn't care for you quite right in the beginning," Gaster continued a little sadly, his smile drooping a bit, "I'm afraid I took the easy way out. I used the generic brand." He paused to reveal a medium-size can of MTT brand enhanced Monster Flakes. "I got the good ones this time," he explained. "It's enriched with vitamins! I don't want that whole one-HP thing happening again." He hummed some more, happily sprinkling the multicolored flakes into the incubation tank as the thing inside - which had already begun to grow considerably larger and was beginning to take on a viable form - squirmed the slightest bit and wriggled its way up toward the soggily dispersing flake food.

"I've tried many times in the past to create my own children, all to no avail - until you, Sans." Gaster placed a hand on the squat skeleton's shoulderblade. "It turns out that what is essential to create a viable soul is...essence!" He smiled wider again, suddenly thrusting the glock-like essence extractor within inches of Sans's face. Sans flinched. "At least one essence must be used, but I used two just in case. You received my sense of judgment, as well as my sense of irony."

Sans stared back at his mentor. His father. "I, uh, sort of get the judgment thing," he said, eyes shifting to the side. As he said it, he knew it was true; he could sympathize with Gaster's urge to detach a judgmental side of himself which, frankly, clashed with his frequently impulsive and borderline narcissistic ventures through the realm of science. Still... "Uh," he continued, somehwat confused, "why irony, though?"

Gaster had returned to sprinkling flake food, humming his odd, trademark four-note hum, onto the surface of the tank's water...or whatever the liquid was. In the back of his mind Sans wished he'd asked more questions about the presence and purpose of this tank before now. "Seriously, Sans?" Gaster said, glancing at his son through his now-dually splintered face. "I'm a scientist who's literally made of magic. It was driving me freaking nuts. Ah," He returned his gaze to the form in the tank. "Splendid! He's coming along quite nicely."

The once-capsule in the incubation tank had somehow already developed into a fully formed head - just a head so far - and it was skeletal and thin, like Gaster's, but with a hinged jaw that kept chomping happily at the flakes floating down.

"He is infused with my empathy," commented Gaster, finally answering Sans's burning question. Sans slowly tore his eyes away from the blissful skull in the tank to once again stare at Gaster. "Along with something else," the taller scientist continued thoughtfully, tilting his head slightly as he regarded his newest creation with fatherly affection. "I can't quite remember." He lifted the essence extractor and inspected the little reading screen with a slightly falling smile. "The readings have already been cleared. I supposed it will have to be a surprise." He shrugged jovially.

Sans's eyes trailed lazily from the tank to the doctor, also deep in thought. "Well, you seem a lot less...screamy," he remarked.

"Hmm. Yes." Gaster's smile widened marginally. "An astute observation, Sans."

They stood there for several minutes, watching as the new skeleton grew. "He's going to be a strong one," Gaster said.

 _CHOMP. CHOMP. CHOMP._

The energetic skull buoyantly hurled itself around the tank, eagerly scooping up every last piece of food in its jaws.

"NYEH!" CHOMP CHOMP. "NYEH!"

Gaster once more placed a hand on Sans's shoulder, the way a human parent might do in the ward of a nursery as they watched their newborn squirm and wriggle its way into their hearts from a distance. "We are a family now," he said, his voice full of gentle pride.

The liquid swirled in the tank, seemingly strengthening the skull as he absorbed it and grew like a bony sponge. "How long does it take for this...Gaster baster...to work?" asked Sans, tentatively tapping the glass.

Gaster shrugged. "Oh, I could crank up the time flow if you really want, but the last time I took a shortcut I ended up with a couple problems. Like, you're really short, Sans." He looked at him, still smiling. "Really, _really_ short."

Sans sighed, shoving his hands into the pockets of his lab coat. He gazed over at his new brother again, this time feeling a strange, new sensation. He could feel his soul resonating with a...familial warmth...as he watched his bizarre brother happily munching away on the MTT flakes. He smiled. He always smiled, but this time it was on the inside too. He had a good feeling about this. And even though he found himself wondering how long it would take for his new brother to fully mature, he realized it wasn't out of scientific curiosity. It was an eager anticipation. And he realized, too, that it didn't mattter to him; however long it took, he would wait.

CHOMP. CHOMP. "NYEH HEH HEH!"

Sans chuckled.


	2. Storytime

Some time passed. How long, Sans did not know.

DORK.

Drifting in and out of sleep, he dreamed in broken pieces.

DORKER.

As his brain processed memories and emotions of the day, unique fusions flickered through his mind.

YET DORKER.

Not all thoughts were accompanied by images; in fact, his most vivid perception was of a blackness which seemed to symbolize either an end to everything or a boundless new beginning, from which there came a silent voice. It echoed in his head:

THE DORKNESS KEEPS GROWING. BROTON READINGS POSITIVE.

An image appeared in the blackness: a skeleton head, jaw slackened in an innocent, unassuming smile, blush tinging the cheekbones like strawberries. The eyes popped wide with excitement and seemed to fill Sans's whole vision. They grew like saucers in his mind, vast and shining and full of potential, like blank new slates for colors of emotion to splash across, or perhaps pasta dishes waiting eagerly for lifenoodles and soulsauce to be slapped upon them. What was this feeling?

Sans blinked himself awake. He was in the shower. Drenched in his lab coat, he had allowed himself to drift off in the chemical shower after having been emotionally drained, and he now watched as the steadily-cooling water rinsed through the semitransparent white fabric of his sodden lab coat and swirled down the drain in a symbolic fashion. After a few further moments of contemplation, he turned off the showerhead, pulled back the purple curtain (purple was Gaster's favorite color), and stared down the seemingly endless hallway toward the door leading back to the main section of the basement level.

Heedless of the slapping squish his slippers made on the tiled floor, Sans made his way slowly across the treacherously impractical length from the chemical shower to the doorway. A trail of slippery footprints followed him all the way through the lower level halls to the popato chisp machine. After a few fumbled attempts at pushing the correct buttons, he managed to accidentally select the Rigid instead of Cripsy ones, and let out a sigh of resignation and collected the bag when it dropped down. He tugged the bag open with less energy than usual, half-heartedly popping a couple of unyieldingly stiff chisps into his face. They somehow phased through the seemingly etched-on permanence of his grin, and despite his preference for different texture he appreciated that this flavor was drastically less ghetto than he was accustomed to. The only other thing he wanted right now might be coffee, but the brewer was upstairs and he didn't know if he had the strength to bring himself up there just yet. He stood for a few long, arduous moments in the foyer, just eating his chisps.

Finally, back on the brightly lit main floor, there sounded the ding of the elevator. It was followed by a metallic swishing noise as the door slid open to reveal Sans, squinting slightly against the increased intensity in light and glaringly vivid memories of recent events, and shuffled out like a snail, leaving a residual trail of moisture in his wake, as well as dropping the empty popato chisp bag somewhere on the floor. He passed by where Gaster sat in a chair by the incubation tank and heard the scientist reciting something, in an endearing, storytelling manner. Something that invoked an oddly bittersweet feeling of nostalgia within Sans. He paused to listen.

"...If this experiment were performed with a measuring rod at rest relatively to the Galilean system K, the quotient would be pi," Gaster read in a lilting voice from a heavy, black hardbound book, glancing occasionally at the skulleton in the tank, who listened patiently. "With a measuring rod at rest relatively to K, the quotient would be greater than pi," Gaster continued.

"PIE!" exclaimed the resident of the tank, his wide jaw opening in a dynamic grin. Gaster responded with a loving smile, rising up a little from his seat to gently pat the skull on the crown. After a few seconds, it further proclaimed, "QUICHE!" Despite being thoroughly submersed in the liquid, his voice rang out clear and loud as a bell on a chalkboard.

Gaster laughed gently and closed the heavy book with a soft thud. He patted the skull once again with loving pride. "Delightful." He turned then to see Sans, who was watching with an oddly blank expression. "Ah, Sans," he said, standing fully and lifting a neatly folded pile of clothes, including one of the shorter lab coats, from the tabletop. He offered them to Sans with an encouraging smile.

"Thanks," Sans said tiredly, taking the dry clothes and letting go of whatever question he had been going to ask. He was currently trying his hardest to remember whether or not these feelings of nostalgia were accompanied by memories of being inside a tank. However, exhaustion quickly got the better of him and he shrugged it off, taking the clothes upstairs to change. Gaster watched him intently.

When Sans got back from his garmental hiatus, sans lab coat, Gaster's eyes widened questioningly at his son. "I'm gonna step out for a bit," Sans explained, eyes skimming down over himself at the slacks and hoodie he was now wearing. He had on his default pink slippers. He recalled, as he continued to stare at them, that he had originally bought these to serve as a prop in his clever pun; he had told Gaster that he had already given himself the pink slips. It had been a half-serious attempt.

"Where to?" asked Gaster.

"Snowdin," Sans replied in an almost slurred voice, rubbing the back of his head. "There's some stuff I need to pick up."

"Wonderful!" Without hesitation, Sans was handed a small shopping list made from a torn-off piece of blueprint paper. Slowly, he glanced down at it. It was written in wing dings. "God damn it," he muttered. As he strained his already withering mind trying remember how to read these things, Gaster had returned his attention to the young skull in the tank. He was staring at it fixedly, with the same smile anyone but Sans would have taken for vacant.

"Seriously?" Sans said after a while, when he had identified the actual listings Gaster had given him. He heaved a sigh and shuffled toward the nearest doorway, indending to take the shortest shortcut possible.

"But not _too_ short," suggested Gaster softly, turning his face a fraction of an inch toward Sans. He was chuckling almost imperceptibly. But Sans was too tired to feel creeped out or indignant about it. He stepped through the doorway and vanished.

No longer than ten minutes later, Sans stepped back through the doorway briskly. He was looking a little better, a little more energetic; he clasped a half-empty bottle of ketchup in his hand, his other arm wrapped around bags of varying sizes. One could clearly be seen to contain another several bottles of Meinz ketchup. There was a bag full of skeins of orange yarn which he didn't even need to deliver to Gaster; the scientist had already whisked it out of Sans's arms the moment he'd come back in through the door. Had he been waiting at that precise spot by the doorway the entire time?

"Feeling better, Sans?" Gaster asked almost as an aside, though he fixed his white pupils deliberately on Sans through the several balls of orange yarn he was nearly juggling in his excitement.

"Yep," Sans replied truthfully, taking another swig of ketchup. "Gettin' there." He deposited the other couple of bags onto the table beside the main lab desk and said, a little too off-handedly, to Gaster, "Why don't you leave the babysitting to me for a little while? I know you must be excited to get to work on...whatever," he said cautiously, eyeing Gaster playing with the yarn, which was now thoroughly entangled in his hands and skull, being thoroughly assessed for quality.

Gaster didn't look up at Sans, but he seemed deeply thoughtful for the new few moments as he reached in and out of the yarn with a seemingly chaotic intensity. "It is...the perfect color," he commented, presumably to himself, such was the softness of his voice. Sans took his responselessness as assent when Gaster wandered off toward a different section of the lab, still carressing the soft fabric of the yarn lovingly between his fingers, muttering something about calculations of predictable dimensions of height and width. Sans and his new brother were alone in the room now. He shuffled over and sat in the computer chair beside the tank, gazing at his skull-bro.

"Hey there," he said in a mellow tone, to which his brother responded by widening his pupilless eyes and strong jaw excitedly. "I'm your brother Sans." Taking another quaff of ketchup from the bottle in his left hand, his right hand dug around in his hoodie pocket and pulled out a freshly-checked-out book from the Snowdin librarby. The skull's eager stare followed the motion in silent awe, bona fide innocence exuding from it almost palpably.

Sans opened the book. He began to read: "Once upon a time, there was a very fluffy bunny." He glanced at his skelebrother in between lines, his reading tone not quite as storytime-like as Gaster's had been, but still melodic enough - as melodic as a voice like Sans's could be, anyway. He tried to make it convincing. "Fluffy Bunny loved to hide. He hid in holes both far and wide. Then jumped out with surprise. Peek-a-boo, I see you, Fluffy Bunny."

The skull's eyes were now becoming larger, shiny and dark and sparkling as he listened. A rosy blush even began to appear on his cheekbones. If he'd had any hands, Sans would swear, they would be squeezed up to his face right now in avid anticipation. Sans tried to put a little more effort into making the next page as exciting as possible. "In the mailbox, in the walls, Fluffy Bunny couldn't be seen at all," Sans dropped his voice an octave, leaning in toward the tank conspiratorially. "Until...peek-a-BOO!" He flashed the book's illustration up to the glass. Fluffy Bunny was depicted leaping out of the fourth wall, which Sans sort of enjoyed as well, and his brother gasped impossibly inside the surrounding liquid of his incubation tank. Sans chuckled.

He turned to the next page with growing anticipa-sans.


	3. Papyrus

Sans slowly awakened to the furious metallic clicking of knitting needles. He opened his eyes groggily, and realized his face was plastered to a book. Carefully peeling his cheekbone away from Fluffy Bunny's snow-white illustrated rump, he lifted his skull to see Gaster sitting in a chair beside him. The second computer chair from upstairs. Gaster must have used telekinesis to bring it downstairs so quietly, which is weird, because it would have been far more in character for him to have just hurled it straight over the balustrade with his long and hyperactive arms, heedless of all physical and social ramifications. He seemed to be slightly more in control of his burning scientific need for instant gratification lately.

"I didn't want to wake you," Gaster said to Sans, turning to look at him with his paternal gaze of intense, endless darkness. He smiled warmly, but it was a little off. Sans couldn't tell for sure, but he thought it was tinged with a sort of...sadness? It was hard to concentrate with the knitting needles still clicking away at manic speed, forming what looked like the finishing touches on a sleeve, Gaster all the while watching Sans with unrelenting focus as he knitted the impossibly complicated stitches. Sans felt he'd had an eerily similar eperience while having a conversation with Gaster one time, many years ago, as the scientist sat calmly at his desk, rapidly typing in codes for alleles to create genetically modified cats. Gaster had not been paying any attention to the screen, Sans recalled, as his skeletal fingers mashed the keyboard with a frantic enthusiasm. He had been discussing with Sans something about how Asgore wanted them to create a companion animal which would be infused with a biological need to receive and reciprocate emotional repression, and therefore, never want to leave Asgore. Sans had asked where the exceedingly enormous amount of funding had gone for this project. Turned out most of it had gone into Gaster's new rave room.

In the end, Sans further recalled, the project had been a disaster. Especially after Gaster kept pressing the enter key multiple times on the 4D printer, furiously making more copies, more versions, determined to create something better. Yet somehow they all remained imperviously identical to the original miscreant. Finally, Gaster tied them all up in a sack and put them in the River Person's boat, and everyone just kind of forgot about them after that. Had they even bothered calling Asgore? Sans couldn't really remember. He only recalled the sense of overwhelming relief once the things were gone.

He didn't feel the same sort of relief right now. Something told him Gaster was telling him something by telling him nothing. And nothing was more telling than nothing. Those knitting needles were still working impossibly and somewhat dangerously fast, jabbing in and out of the lines of yarn with manic yet compassionate direction. Sans's eyes traveled over the strangely long garmet his mentor seemed to be creating at a lightning-fast pace, crafted with perfect precision. He seemed to be nearly finished with the project; he was just now finishing the cuffs of the sleeves. Sans began to turn his head sleepily toward the tank, when suddenly Gaster threw the knitting needles into the air and heaved himself out of the chair, arms flailing and waving the bright orange creation like a warning flag.

"Don't look, Sans!" Gaster cried. "He is indecent!" There was the sound of the aluminum knitting needles clattering somewhere at the far end of the lab.

Taken aback, Sans jumped in his seat. Thoroughly confused and perturbed, he whisked his head around to try and find out what-

Sans screamed. He stared at his once-skull brother in the tank, and the skull stared back with the same perpetual innocence as it had always possessed. Except now it wasn't just a skull. It was a fully grown skeleton. Even taller than Sans. Yet he was still sitting patiently in the tank, knees drawn up to reserve space, with his arms wrapped around them in an very childish way. He was gazing expectantly at Sans. His face, now bone-dry, was level with Sans's. Staring.

"GOOD MORNING, BROTHER!" he screamed.

"He is waiting to hear the rest of the story," Gaster explained to Sans, allowing his freshly-incubated garment to drape toward the floor to its full length. He didn't even bother checking the measurements or craftwork; he already knew it was perfect. "But now is not the time!" he cried, swiveling to stare at his newset son. "Papyrus!"

"YES?" answered the skeleton excitedly.

"Rise, my son! _Rise!_ " He whipped his head around. "Sans!" he yelled at the shorter skeleton in an almost accusatory tone, "Turn your visage!"

Sans, perplexed and overwhelmed, turned his head as Gaster pulled the perfectly-knitted sweater over Papyrus's standing body in one fell swoop. It ended just above his knees. His ankles were still submerged in the tank. Only his ankles. As Sans slowly turned back to face them, he realized how tall his brother had inexplicably become overnight...or over...whatever. How long had it been? Christ, how long had he been out for? He cast a fleeting glance at the empty ketchup bottle on the other side of the desk with a growing sense of regret.

"You...named him Papyrus?" asked Sans.

"What!?" Gaster exclaimed indignantly. "Of course not! His name _is_ Papyrus. Can you not see this, Sans?!" The doctor's expression changed to a combination of disbelief and shame as he regarded his first-born son. He leaned in closer, slowly. "I expected better of you, Sans," he mumbled in a disparaging tone.

Sans, brow furrowing sternly, raised his hands in the air in an offended gesture, but Gaster was already ignoring him in favor of his newer, taller son. He telekinetically lifted Papyrus out of the incubation tank and kept him hovering in the air for a moment while he also magically withdrew a pair of his own black slacks from a drawer in the corner, as well as a large pair of shiny floral-patterned gardening boots (which Sans was pretty sure belonged to Asgore). Then he positioned all three of them in order linearly, and plunged Papyrus downward through the pants and into the boots. Everything fit perfectly. Papyrus's smile did not falter throughout the rapid transition. In fact, he smiled yet wider, as he screeched, "I LEARNED A PRIVACY!"

"Indeed." Gaster leaned in to hug his newborn son with fatherly love and a scientifically calculated dispensation of comfort. A long moment passed. "I love you, son."

Papyrus's smile grew even wider. His eyes widened as well, filling with wonder. "ARE YOU GOD?"

Gaster's smile froze. He didn't seem to know quite how to respond for a moment, wringing his hands slowly and awkwardly. The distant stars of his white pupils flickered almost imperceptibly brighter as he slowly turned to Sans. "Perhaps now is an excellent time for you to finish reading him the story, Sans," he said in a very normal Gaster voice.

Papyrus gasped with excitement. He rushed over on his very sturdy, stable new legs to grasp Sans around the middle in an intensely brotherly hug, lifting him a few inches into the air as he did so. "STORY TIME!" he bellowed.

Sans, despite the weirdness of his current predicament, felt cool with it. "Sure thing, bro," he said, patting his younger brother on the back with what little movement his arms were allowed through the forcefully binding embrace of his brother's arms. "But, uh, before we crack open the spine of that book, you gotta stop trying to crack open _my_ spine," he chuckled wheezily.

Papyrus deposited Sans on the clean, white floor very, very gently. He then went to the table to retrieve the book, which he held almost reverently in his eager skeleton hands. It was already open to the very page Sans had passed out at. Papyrus stared down intensely at the illustration for a good solid thirty seconds, his eyes growing wider and more sparkly with each passing second, until he finally gazed up at Sans. "I CAN'T READ."

Sans smiled, took the Fluffy Bunny book and led Papyrus over to the two computer chairs, neither of which was occupied by Gaster, who had seemingly disappeared to some other room. Sans shrugged. Papyrus was waiting. They got comfortable on the chairs. Papyrus was spinning around in his slightly in anticipation.

"Unfortunately, there's only a couple pages left, bro," Sans said as a disclaimer, carefully turning to the next page. He tried to slip into his awkward storytelling voice, which was still kind of hilariously monotonous despite his best efforts. "Can you find Fluffy Bunny?" he read, now able to show the pictures directly to Papyrus as they sat together. This picture was of a snowy field, which seemed to be entirely blank and white. There was no such promised rabbit to be seen. Papyrus squinted hard at it, trying to figure out the puzzle. "Perhaps you can not peek-a-boo..." Sans read slowly, turning to the next page even slower, "...because Fluffy Bunny's peeking YOU!" He whipped open the last page, where a cardboard 3D pop-up of the deviously fluffy protagonist literally jumped out of the book. The illustrated snow from before had proved to be nothing more than an elaborate ruse. Papyrus screamed.

"OH MY GOD!" he leaped out of his seat with such energy that the computer chair spun across the floor on its wheels and crashed into some graduated cylinders of colorful liquids. "HOW DOES FLUFFY BUNNY DO IT?"

Sans was laughing, half in amusement and half in shock; there was somehow so much Gaster in this guy, in a cool way. He was a gas. He was still laughing when the book was nearly ripped out of his hands as Papyrus turned it around in every possible direction, opening and closing the popup page with less and less satisfaction and more and more intrigue. "I, THE GREAT PAPYRUS, WILL SOLVE THIS PUZZLE!" he exclaimed, brow furrowed in deep-set resolve. "THE MYSTERY OF HOW THIS BUNNY SOMEHOW MANAGED TO TRAVEL FROM THE SECOND DIMENSION TO THE THIRD!" He squinted at it hard, yet lovingly. His eyes widened gradually, the happiness sparkles returning to them, and the pink tinge once more setting on his cheek bones. "HOW IS THIS POSSIBLE?" he whispered. He then, despite himself, hugged the book close to his sweater-clad chest, inadvertently crushing the pop-up against the soft vermillion fabric.

"I guess some bunny had bigger plans," suggested Sans with a shrug.

Papyrus whirled around, disbelief and shock replacing his once-innocent face. "THAT WAS TERRIBLE!" he cried indignantly. He paused, frowning. "WHAT IS THIS FEELING? I AM FEELING..." His jaw widened slowly as his soul processed whatever emotion was currently being forced upon his existence. "...ANNOYANCE!" he decided, his eyes becoming yet more frowny and disapproving.

He carefully placed the precious book back down on the table, walked over to Sans, knelt down to his height, and tenderly placed his arms around his squat brother, embracing him far less spine-shatteringly than the first time. It was a gentle, comforting hug. "IT IS ALRIGHT, SANS," he yell-whispered into his brother's ear hole. "I FORGIVE YOU. AND I STILL LOVE YOU."

There were two things Sans was not used to: being told off for his puns, and hugs. But, strangely, there was something nice about being told off for making bad puns. In fact, he liked it so much, he was going to keep making bad puns just to get this feeling again. Making them worse, and staler, and...

"I love you, too, Papyrus," he said slowly, with a wide grin.


	4. Pappy Birthday

Sans rummaged through the first-floor refrigerator, searching for something appropriate for their breakfast. Unfortunately, there wasn't much to choose from. Half the fridge was filled with bottles of Gasterade; Alphys's weird variety of soda bottles were lined up in order of sugar content in the tray of the door, along with several packages of instant noodles; the rest of the space was occupied by twenty-nine hotdogs and a bag of take-out from Grillby's. A few packets of Gaster's flavor text were stored in the spice drawer. Nothing breakfasty. He shrugged, pulled out the greasy paper bag with the flame logo on it, and set it on the table next to the microwave with a hesitant glance at Papyrus, who was watching him squintily. Papyrus was not pleased.

"SEEING AS IT IS MY BIRTHDAY, I THINK I SHOULD GET TO DECIDE WHAT IS FOR BREAKFAST." He crossed his arms stubbornly, which didn't get across the same effect of authority it might have if he'd not been wearing an adorably fluffy sweater. The stitches formed little patterns of hearts and bones.

"Whatever you want, man," Sans conceded, stepping back from the fridge and allowing Papyrus to thoroughly peruse the contents on his own. While his brother chaotically swept aside bottles and packages in the refrigerator with intense purpose, seeking nourishment appropriate for such a monumentous occasion, Sans proceeded to stick the Grillby's bag in the microwave and set it to 'flaming hot.' He pushed the button and watched as the bag slowly rotated in the glow of the microwave light, then burst into flames as it was designed to do, gradually burning away the paper bag to crispy cinders and leaving behind a delicious (yet greasy) meal of burger and fries to be had. The microwave beeped.

As Sans retrieved his still-smoldering food from the microwave, he threw another glance at Papyrus, who was still throwing things aside in frustration within the fridge. Finally, with a small degree of resignation, he withdrew a bottle of Gasterade (it had a picture of Gaster's face on it) and a package of the instant noodles (which technically belonged to Alphys, but Sans wasn't going to deprive his brother of anything on his 'birthday,' even if they were...exceptionally un-nutritious noodles). Sans could already tell Papyrus had some high standards when it came to certain things. Like this. Like by the way he was grimacing at the questionable products in his hands. This was clearly not the way he had envisioned the first day of his intensely awesome life.

Sans reached for a different bottle of soda from the door of the fridge. "Hey, bro," he said, while slowly but surely rocking the root beer behind his back (enough to build up some tension, but not too much). "Why don't you try this one instead? That stuff is way too purple for my taste." He indicated the bottle of Gasterade with a tired glance.

Papyrus immediately accepted the trade. "IF IT IS MORE TO YOUR TASTE, BROTHER, THEN I SHALL GLADLY TRY THIS INSTEAD!" Papyrus set the bottle firmly on the counter and eagerly popped off the cap with his multi-purposeful thumb. However, once he had, a sudden gush of sugary foam burst out of the top like a tiny volcano, covering Papyrus's hands and almost getting on the cuffs of his sweater.

"GAH! THIS IS NOT SUPPOSED TO HAPPEN!" Papyrus knew.

Sans was chortling heartily as he watched, then felt slightly guilty as Papyrus glared at him. "It _is_ more to my taste," admitted Sans with a shrug. "It's just a harmless birthday prank. Birthday pranks are things. Like a surprise party. Except the party is sticky."

"I SHOULD HAVE KNOWN YOU DON'T ACTUALLY LIKE THIS QUESTIONABLE BEVERAGE!" yelled Papyrus in a moment of overdramatic clarity. He gasped in sudden revelation. "NOT ONLY DO YOU LIKE BAD PUNS, BUT YOU LIKE ALL KINDS OF BAD JOKES!" He then looked down at his hands, which were still dripping slightly with soda, and heaved a sigh. "IF IT WERE NOT FOR MY CURRENT PREDICAMENT, I WOULD ONCE AGAIN EMBRACE YOU IN REASSURANCE, BROTHER. I STILL FORGIVE YOU, BECAUSE CLEARLY YOU CAN NOT HELP YOURSELF. BUT I AM TOO SODA AT THE MOMENT."

Sans watched as his brother struggled with the desire to roll his eyes only to discover he had no eyes to roll, then figure out how to portray his newly processed feelings of exasperation in another way: by squinching his eyesockets and slightly lowering the hinge of his grinning jaw. It was very effective; Sans could really feel the cycle of irritation he had set into motion. Part of him still wanted to laugh, but he felt too guilty now. Papyrus was just so...innocent. At the same time, he was getting this weird sense that he should continue to prank Papyrus in little, harmless ways, to prevent him from developing the same narcissistic flamboyance that Gaster sometimes displayed. Sans felt that this was a very real possibility, because -

"I, THE GREAT PAPYRUS, HAVE ELECTED TO GRANT YOU PITY!" Papyrus suddenly declared, striking a bold and prideful pose in front of the refrigerator. "I SHALL NOT LOWER MYSELF TO THE LEVEL OF PETTY RETALIATION IN SUCH MATTERS."

My God, thought Sans, it had already begun.

This was something he would have to deal with later, he thought, as he shrugged off his hoodie and switched it out on one of the wall hangers for his short lab coat, which, it seemed, Gaster had inconspicuously replaced at some point. A way of telling Sans to get back to work upstairs, perhaps. Sans sighed as he pulled his arms through the white sleeves of the (dry) lab coat, trying to juggle several different things in his mind at once, like how he was going to handle both Papyrus's birhday and getting his usual labwork done. And how he was going to handle Papyrus in general, he supposed. although the newborn skeleton seemed competent enough on his own (Papyrus was still striking his overconfident pose as he meticulously figured out how to open the package of instant noodles). But then a memory made Sans pause. For some reason, he was associating this current juggling of situations with the juggling Gaster had done with the balls of yarn. What a weird thing to associate. And he began to shrug it off much as he'd just shrugged off that hoodie - but then he also realized something felt off to him about how Gaster had placed Sans's dry lab coat here wordlessly, in the perfect place for Sans to find once he'd shown his brother to the fridge for breakfast stuff. So that Sans would go back upstairs and continue on with his daily work... Sans heaved a large sigh as he contemplated this. Was he overthinking things again? Gaster had been gone for a long time. Did Gaster not want Sans to investigate his absence?

As he was further contemplating, Sans did not realize at first that Papyrus had opened the microwave and was currently sticking his own head inside of it, examinining it thoroughly. "IT IS LIKE AN INCUBATION TANK FOR FOOD!" Papyrus proudly guessed, profound wonder in his eyes. He kept his head _inside the microwave_ along with the instant noodles (which he'd figured out to put in a little bowl, although without water) while he began blindly hitting random buttons on the outside of the microwave with his free hand. Extremely swiftly and inconspicuously, Sans ripped the plug out of the wall connecting the microwave to the outlet. His brow creased in a slight frown as he regarded his brother now with more than slight conern, wrapping the microwave plug around the table leg and jamming it up inside the back compartment of the desk just to make sure it would not be rediscovered any time soon. The thought at the forefront of his mind right now had definitely become this: find Gaster. There were bad times to be had if Gaster were not around to supervise Papyrus today.

Papyrus did not notice that the microwave was no longer functional, and he continued to hit every button on its display with furious eagerness as Sans backed slowly across the room toward the elevator, feeling confident that Papyrus would be all right by himself for the next few minutes, at least; most of the doors were locked. It's not like Papyrus had a passcode for the doors yet or anything... Then Sans sighed yet again, in mild regret, as he accepted the fact that his brother would have to spend his birthday breakfast alone, sans microwaved noodles. Oh, well. They were better dry anyway.

Sans pushed the button for the elevator, still watching as his brother synchronously pushed the "flaming hot" button on the unresponsive microwave, before the elevator doors shut and Sans began to descend, beginning his errand of finding Gaster.


	5. Stark Raving

There was a beat echoing softly from somewhere far in the distant reaches of the basement level of the lab. It grew louder and more intense as Sans walked, hands resting in the pockets of his lab coat. As it intensified, so did Sans's anxiety. What day was it, again? Saturday. So, then, why...

...His slipper-padded footsteps echoed in unsettling dischordance with the beat. The lights overhead flickered eerily as something drew power from the entire lab's electrical supply. Sans had never known something to be strong enough to draw this much power before. The lab's main power was hooked up directly to the Core itself; there was so much magical energy directly flowing in that an effect like this could only be caused by something...huge.

...

By the time Sans reached the rave hall, the beat had become bone-vibratingly loud and more intense than Sans could handle with the headache he'd been steadily developing from the anxiety of having watched Papyrus nearly microwave his own face off.

The mirrors lining either side of the hallway reflected countless brilliantly neon orange and blue laser lights, the blue ones frozen in stillness as they spanned the room, reflecting over and over; the orange ones moving fast and hitting the reflection points on the glass in perfect time with the beat of the music. Strobe lights flashed overhead as well, plunging the hall into darkness and back into blinding white with rapid pace. It was irritatingly miraculous to behold. The timing of the lights was perfect. The precision of the lasers in synchronicity with both the music and the mirrors was impossibly accurate.

In the middle of it all existed Gaster, gloriously and powerfully dancing his heart out in his black rave robe. Bending and swooping in and out of the way of the lasers as they crossed over the space his spookily graceful body occupied. In and out, left and right and backward, he raved with utter perfection. The explicitly dangerous touch of the lasers never once grazed him, despite their rapid changes in formulaic sequence; he was far too precise in his manic energy. He was a magical raving scientist.

The music was like Another Medium entirely. It transcended the Barrier of expectations set by reality itself. Almost as if it were composed by and of Gaster himself.

Sans basked in the glory from afar, not wanting to enter the hallway himself for obvious physical reasons. Like, he knew what those lasers could do, and it almost terrified him to watch Gaster so close to danger in this way, but at the same time, he knew Gaster would never falter in his precision; dancing manically through his feelings was simply how he relaxed. Even if those lasers did hit him at any point, Sans considered, they probably wouldn't hurt him much. Hell, even a kid probably wouldn't die from it until a few good hits in. Sans subconsciously wondered how many hits it would take to really give them a bad time.

Within the colors within the rave hall within the darkness, Gaster was in his elements. Well, most of them. Two of them were inside Sans at the moment permanently, because they were sort of essential for his existence. Another two were upstairs, presumably assisting in still trying to figure out how to work a microwave.

Despite his immersion in the multi-leveled world of immaculate melody he'd created, Gaster noticed when Sans cleared his throat.

Sans didn't technically have a throat, but this was important.

The doctor whirled around, the black trail of his robe whipping around with a flourish as he ceased his raving abruptly. The lasers immediately turned off, and Sans wondered if Gaster had flipped a switch on the wall behind him telekinetically, but it was hard to think or wonder about anything at all over the intensely loud music, which, along with the strobe lights, persisted.

"Sans," said Gaster softly, his smile amost nonexistent. "I did not wish for you to see me like this."

"WHAT?" Sans tried to yell over the music.

" _I did not wish for you to see me this way,"_ Gaster tried to scream over the intense rave music. When he remembered he could no longer screech out his eloquent responses as he used to, he reluctantly walked over to the sound panel on the wall and turned off the booming and slightly shaking speakers. Then he turned to Sans, but was not really facing him. His sad smile was essentially a vertical slash of reluctance now as he gazed sadly in the general direction of his son.

"I still didn't hear what you said, G," Sans prompted.

It took Gaster a long moment to respond, which was unusual in itself. Finally, he turned his dark eyes up to look at Sans with absolute contrast to the energy he'd been displaying a minute ago. He looked...forlorn, somehow. This expression had never crossed his face before. Sans stepped closer, now pretty comfortable with the fact that the lasers were gone. He stopped a couple of meters from Gaster, giving him space. He felt...unsure about what Gaster wanted him to do.

"I want you to be more careful, Sans," the tall, darkly clad scientist said softly. His pupilless eyes were not boring into Sans with their usual manic intensity. It was more of a manic melancholy. "You should not have come here in the midst of my intensely brilliant and scientific raving. You have only one HP. And you are...less than dexterous. You do not have ample agility. And your sense of rythym is lacking. And-"

"Gaster," Sans said in his monotone. "What's wrong?"

Slowly, Gaster began to regard Sans with a growing light in his eyes; the little starlets of his pupils began to show. Yet he hung his head again, as if in shame. Another moment passed. "I did not notice at first in my enthusiasm," he said, slowly but clearly, in an almost detached, clinical manner which he usually reserved for speaking to Alphys, "that you had purchased a disproportionately large number of ketchup bottles on your excursion." At the end of the detached tone, the sadness had begun to seep in.

Sans's eyes slowly shifted toward the mirrors on the other side of them, in an attempt to distract himself from the awkwardness of the situation. Unfortunately, since they were mirrors, the awkwardness intensified exponentially, because he could now see many reflections of Gasterly sadness and awkward Sansness.

Gaster suddenly put his hands (which had glow bracelets strung through the holes?) over his face. "One time," he began, in a slow and dramatic tone, "I was eating a hamburger."

Another long moment passed. Sans waited, but Gaster didn't say anything. The strobe lights were flashing epileptically against the sombriety of the moment. "Gaster -"

"I did not consider the potential repercussions of my rampant negligence," blurted the doctor over his son's dull voice, "of the possibility that this reckless snacking may result in an unintended consequence outside of the controlled and perfect atmosphere of my brilliantly constructed incubation tank." He paused now, glow-braceleted palms sliding slowly down his face as he stared directly at Sans. "A dallop of ketchup fell in."

Sans furrowed his skelebrows. "What."

Gaster made a tiny, weird anguished noise in the back of his face and squeezed his asymmetrical eyeholes into a sort-of frown, though he was technically still smiling, and his arms wiggled up over his head forlornly. " _Sans you have inherently developed a biological requirement for fermented tomato-based condiments as a result of your tainted incubation cycle!"_ He immediately covered his face with his hands again, the green and purple glow of the bracelets reflecting through his skull from his hollow sockets.

"...Wait a minute." Sans was thinking very hard about something...revealing. "Does this mean..." He slapped a hand to his foreskull in exasperation, realization dawning.

"Yes," said Gaster. "You have a unique biological reaction to ketchup."

"So _that's_ why Grillby looks at me funny."

Gaster was sobbing dryly into his glowsticks. Somehow, through his shock at this revelation, Sans managed to shuffle closer and place a hand on his mentor's darkly-clad shoulder. "It's okay, G," he said. "I, uh, kinda wish you'd told me this before? But I understand. Listen," he rubbed the back of his skull awkwardly, "I, uh...I wasn't sure at first how to feel about all this. Like, being born in a fish tank? But I understand now." He was going to kneel down to where Gaster was hunched over, but realized he was actually still shorter than Gaster, and so the doctor knelt down further instead, through his sobs, to be at equal eye-level as his son spoke. "This whole fish shtick is okay with me. Papyrus is actually...really awesome. I was just worried at first that...y'know, because you get a little cra-" he abruptly stopped himself, searching for a better word, "-excited sometimes, maybe this wasn't the most well-thought-out project."

Gaster abruptly stopped sobbing. His eyes flickered up to Sans with startling clarity, the lights of his pupils gone entirely. "Sans," he said. "Ssssaaaannnsssssss."

"What?"

"That is boo sheet, Sans."

"What."

"It is boo sheet," Gaster repeated, now grabbing Sans slowly by the shoulders. "You're blooking at it all wrong."

Sans squinted narrowly at his father. "Have you been hanging out with that guy again?" He then cast his squint at the soundboard on the wall, which had clearly been recently upgraded. A set of headphones lay nearby.

"That is not important!" Gaster cried, shaking him slightly. "What is important, Sans, is that you understand how spoopid it is to think this way. Your life is no less significant just because you were born through my ingenius incubation technology. Don't be spoopid, Sans."

Sans heaved a sigh. "That's not what I was going to say."

"But it is what you were thinking!" Gaster insisted, shaking his son yet again, though very gently. He then clasped Sans very slowly and firmly to his chest, patting him on the skull slowly and deliberately. "It is all right, Sans."

Sans rolled his eyes. He had pretty much resigned himself at this point to Gaster's emotional outburst and was currently trying to think of a way to extricate himself without hurting G's feelings. Because he had a pretty good feeling that this could go on for a while. "Gaster...it's okay. I'm cool with it. Really."

"Life is precious, Sans," whispered Gaster, still petting Sans's head. "You don't need to ketchup to anyone's expectations." Suddenly, he held Sans at arms' length, staring. "You did finish your work today, didn't you?" When Sans didn't answer, Gaster once again tried to pull him into a fatherly embrace, but Sans pushed back with what little G-force he had. "I really appreciate what you're telling me, Gast, but I feel like we should both get back upstairs as soon as possible. I mean, can't you save this for your Sunday rave instead?"

"Every day is son day now," replied Gaster with an increasing smile. He looked much better.

The strobe lights were still flashing overhead.

Sans, yet again, sighed.

...

...

MEANWHILE . . . . . . . . . . .


End file.
